Qassim Hassan, 23, threw the package containing heroin and crack cocaine during a struggle with officers in St Bartholomew’s Court, Cambridge, on the evening of August 12.

But an eagle-eyed witness spotted the package in the water.

A fisherman leant officers a net and the package, containing about 40 wraps of heroin and crack, was fished out of the river.

Hassan, from Hayes, Middlesex, had been originally stopped and searched by officers but tried to run off after they found a package hidden down his trousers. A struggle ensued during which Hassan threw the package under the police van. His friend then tossed the drugs into the river.

Another package containing about 50 wraps was recovered from Hassan’s trousers.

Hassan pleaded guilty to two counts of possessing class A drugs with intent to supply, possession of a class B drug and assaulting a PC with intent to resist arrest.

He was jailed for a total of three years and four months at Huntingdon Crown Court yesterday (Thursday).

Detective Constable Tom Taylor said: “Hassan tried to throw away his drugs but thankfully a member of the public saw what happened and alerted the officers who were able to recover them from the river.

“Drug dealing will not be tolerated in Cambridge and we will continue to ensure that dealers who come to the city to sell drugs will be arrested and put before the courts.

“We would continue to urge people to report any suspicious activity to police.”